Reluctance controlling means



Feb. 7, 1933. c, H. zlERDT RELUC TANCE CONTROLLING MEANS Filed Feb. 24, 1930 2 Sheets-Sheet l INVENTOR ATTORNEY Feb. 7, 1933.

C. H. ZIERDT 1,896,436

RELUCTANCE CONTROLLING MEANS Filed Feb. 24, 1930 Sheets-Sheet 2 Q ff @9,2

Patented F eb. 7, 1933 lUIJITED STATES PATENT OFFICE- CONRAD H. ZIEBDT,VOF ROSEDALE, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH t SIGNAL COMPANY, 0F SWISS'VALE, PENNSYLVANIA, A CORPORATION OF PENNSYL- 'VANIA RELUCTANCE OONTROLLING MEANS Application led February 24, 1930. Serial No. 430,579.

This invention is concerned with means for controlling the reluctance of a path for magnetic flux. lOne of the objects of the invention is the provision of improved means for .5 controlling flux in a magnetic circuit by varying the size of air gaps in such magnetic circuit, which means shall be inexpensive to manufacture, simple in construction, and susceptible of convenient and expeditious operation. Another -feature of the invention resides in provisions whereby the movable element which is shifted to vary the size of the air gaps may be guided and steadied in its movements and may further be readily removed to facilitate cleaning of parts. Other features of the invention will be here inafter described and claimed. l

In the accompanying drawings I have shown an embodimentof my invention in connection -with a transformer forming part of a rectifier unit of the type frequently used for charging storage batteries; the transformer changing the line voltage to suitable rectifying voltage. My invention is particularly useful yfor varying the voltage supplied by the transformer to the rectifier whereby the charging rate of the latter is varied; but it will lbe understood thatthe utility of the invention is .by no means confined to the example shown and that the invention is useful inconnection with transformers or reactors generally or wherever variation in the yreluctance of a path for magnetic flux is desired.

f vIn the drawings:

Fig. 1 is a view in end elevation showing an embodiment of my invention in connection with a transformer and rectifier unit.

Fig. 2 is a plan view of a portion of 4the structure shown in Fig. 1.

Fig. 3 is a view of said structure in front elevation.

Fig. 4 is a fragmentary view in side elevation showing the reluctance varying means in a different position from that shown in Fig. 3.

Fig. 5 is a detail view ofthe movable block whereby the reluctance is varied.

Referring to the drawings the transform- 59 er-rectier vunit in connection with which my invention is illustrated comprises a housing 2 for the rectifier and a transformer 3. The rectifier is not shown since it forms no part of the present invention. The transformer comprisesa laminated core 4 of magnetic material having parallel horizontal leg portions 5, 6, suitably spaced to permit the respective primary and secondary windings 7, 8, of the transformer to be wound therearound. The upper portions ofthe laminations of said core are clam ed between front and rear plates 9, 10, by bolts 11; while at their lower ends said laminations are fastened together by bolts 12. The transformer is shown secured to the rectifier housing 2 by bracket members 13, 14, each of which is fastened at one end to said housing by a bolt 15 and at its other end to the plate 10 and core 4 by one of the bolts 11.

In carrying out my invention I provide the core 4 with a shiftable upper portion in the form of a block 16 of magnetic material. This block overlies the spaced extensions 4, 4 of the core 4 and provides a path for the flux from one of said extensions to the other. Said block may be made up of laminations secured together by bolts 17, 18. Each of the plates 9, 10 is provided with a pair of notches 19, 20, having curved or camming surfaces for cooperating with bolts 17, 18. When the block 16 is in contact with the top of the core 4 the bolts 17, 18, occupy the `positions shown in Fig. 3. It will be seen that if ythe block 16 is drawn toward the right (as viewed in Fig. 3) the vcurved surfaces of the notches 19, 20 will act upon said bolts to raise said block, the extent to which the latter is lifted increasing as the extent of travel of said block to the right increases. In other words, by shifting the block 16 to the right an air gap is produced between the block and the extensions 4', 4 of core 4, the size of which gap depends upon the extent of longitudinal movement of said block. In Fig. 4 the block 16 is shown moved slightly to the right of its position in Fig. 3, and it will be noted that the block has been raised slightly with respect to the core 4. It will be apparent that shifting of the block 16 varies vthe reluctance of the V pathV for the magnetic iux which passes through said block, so that the flux passing through the Winding 8 is varied and the electromotive force induced in said wind? ing is correspondingly altered.

The block, 16 is shown provided with an uppernotch 21 curved complementally to the notches 19, 20 so that as said block is moved the surfaceof` said notch 21 bears against a bolt v22" extending through the upper portions'of the plates, 9, 10. Said block 16 bears against said bolt 22 at all times and is thereby steadied duringV its movements. Movement of said block to the right may be limited by the contacting with bolt 22 of a shoulderl 23 at the left of the notch 21; or by engagement oil bolt 17 with a shoulder portion 24 of the notch 19; `Movement of block16 tothe left may be limited by the engagementl of bolt 18 with shoulder portion 25 of notch 20.` r i :F01- Shiaing'thebioek 1e ihm diseased ders 29, on opposite sides of said bracket for preventing longitudinal movementY of said sleevel It-will be evident that by turn-V ing said sleeve in the appropriate direction the block 16 may be shifted either to the right or tothe left, and the reluctance of the magnetic u'x path-varied accordingly. Very accurate adjustments of the position of the block 16 with respect to core t are obtainable through the sleeve 27 and rod 26.

- VThe block 16 may be provided on its under surface with a notch 31, which serves to accelerate the change in reluctance of the magnetic flux pathduring movement of the block to different positions. v j j 1 It will be seen that inasmuch as the notches 19, 20 are openthroughout the major por-v tion of their lengths the block 16 may be readily removed whenever desired by simply removing the bolt 22, disconnecting the rod-26.

l irom'bolt 17, and'manually withdrawing said block from its-positionbetween the plates 9 and 10. y Y a f Whiler I have disclosed an embodiment of my invention in connection with a transformer, it will be apparent that it is equally applicable to the variation' of magnetic reluct- 1 ance-'in Vother devices. For example, it may be applied to reactors for varying the amount of flux passing through'the reactor winding and thereby varying the reactance of the latter. In this connection it may benoted that if the lower windingV 7 and corresponding lower part of core 4 be' omitted, the resulting structure 'constitutes areac'tor and it will be obvious that the block 16 may be utilized to vary the reluctance of the flux path in said structure in the same way as in conjunction tions are possible within the scope of the invention claimed. Y

VWhat I'claim is: y

1.V In combination, a magnetizable core comprising a fixed portion carryingV a winding and a movable portion forfvarying the reluctance of a path for magnetic lux associated withsaid winding, a plate secured to said iixed portion and havingV a plurality of curved Vnotches therein, a plurality of projections on said movable portion each cooperating with one of said notches, and means comprising a notch in said movable portion andk a projection on said plateV for steadying said movable portion during its movements.-

2. In combination, a Amagnetizable core comprising a fixed portion carrying a winding and a movable portion for varying the reluctance of a path for -magnetic fiuxassociated with said winding, a-plate secured to said iixed portion and having a plurality of curved notches therein, a plurality of proj ections insaid movable portion, each cooperating with one of said notches, andmeans for steadying said movable portion during its movements, said means comprising a projection on said plate anda notch in said movable element curved complementally to Vthe Y notches in said plate.

3., In combination, la magnetizable core made upof a fixed portion carrying a winding and a movable portion for varying the reluctance of a path for magnetic iiux associated with said winding, a bracket attached to said xed portion, an interiorly threaded sleeve passing through said bracket and provided on opposite sides of the bracket with shoulders, a rod threaded in Vsaid sleeve and attached to said movable portion, and means responsive to movement of said movable portionrin one direction resulting from rotation of said sleeve to move the movable in another direction. Y

Y 4C. In combination, a magnetizable core comprising a xed portion carrying a Winding and a movable portion for varying'the portion reluctance of a path for magnetic fluxV associated with said winding, a plate secured to said xed portion and having a plurality of curved notches therein, a plurality of pins in core portion from the fixed portion, means comprising a portion of one of said notches cooperating with the associated pin for limiting movement of said movable core portion in one direction, and means comprising a portion of the other of said notches cooperating With its associated pin for limiting movement of said movable core portion in the opposite direction.

5. In combination, a magnetizable core comprising a fixed portion carrying a Winding and a movable portion for varying the reluctance of a path for magnetic ilux associated with said Winding, said movable portion being composed of laminations of magnetizable material, elements for securing said laminations together, means comprising curved open notches having a given relation to said fixed portion and engaging said elements respectivelv for varying the distance between the fixed and movable portions in response to longitudinal movement of the latter, means comprising a portion of one of said notches for cooperating With the associated element to limit movement of said movable core portion in one direction, and means comprising a portion of the other of said notches for cooperating with its associated-element for limiting longitudinal movement of said movable core portion in 'the opposite direction.

In testimony whereof, I have signed m name to this specification this 19th day of February, 1930.

CONRAD H. ZIERDT. 

